Okay so my first question is this: what are the advantages of having an actual 1911 .22 vs a .22 conversion kit for my 1911 and vice versa?

I already have a 1911 in .45 but I want to be able to shoot that platform with a .22LR.

My second question is this: what is the cheapest priced quality conversion kit? I am well aware of the Advantage Arms and the Marvel kits. Marvel kit is out of the question because for the price I can just get a new pistol.

The features I consider "quality" are a slide that locks back on the last shot, and reliable. I would prefer it to actually look like a 1911.